Diaphragm and sound amplifier



July 8, 1969 R. N. ALESON I DIAPHRAGM AND SOUND AMPLIFIER Filed May 24, 1967 I N VEN'TOR.

i ftjzuies Patent 3,454,281 DIAPHRAGM AND SOUND AMPLIFIER Robert N. Aleson, Sylmar, Calif., assignor, by mesne assignments, to Lorraine Industries, Inc., Bridgeport,

onn.

Filed May 24, 1967, Ser. No. 640,918 Int. Cl. Gllb 3/00 US. Cl. 274-1 6 Claims ABSTRACT OF THE DISCLOSURE A phonograph device adapted for toys reproduces sound by mechanical actuation of a diaphragm, and an enclosure for the diaphragm defines a sound chamber with the diaphragm and acts as a baffie. The enclosure is apertured opposite a main portion of the diaphragm and imperforate opposite an auxiliary apertured portion of the diaphragm, and a bafile wall partially partitions the sound chamber between the main and auxiliary diaphragm portions.

This invention has to do generally with phonograph devices adapted for use in toys and particularly with means for increasing or amplifying the sound emitted by such devices as reproduce sound by direct mechanical actuation of a diaphragm.

An object of the invention is to provide a novel means for enhancing and amplifying sound produced by the vibrations of a mechanically driven diaphragm of a phonograph means.

Another object is to provide an improved diaphragm which in and of itself provides louder, more distinct reproduction.

A further object is to provide a novel enclosure in conjunction with the diaphragm for the purpose of increasing the sound or amplifying it and giving better reproduction.

A more particular object is to provide a novel construction for amplifying the sound of a miniature or toy phonograph or other sound device employing a sound diaphragm as a wall of a closed or substantially closed case housing the working parts of the device.

These and other objects will be apparent from the drawings and the following description. Referring to the drawings:

FIG. 1 is a plan view of a small mechanical phonograph device embodying the invention;

FIG. 2 is a side elevational view of the casing of the device of FIG. 1, but on a larger scale and with the casing broken away and a central sectional view through the diaphragm and walls thereabove;

FIG. 3 is a fragmentary sectional plan view on line 3--3 of FIG. 2;

FIG. 4 is a fragmentary cross sectional view on 'line 44 of FIG. 2;

FIG. 5 is a view similar to FIG. 3 but showing an alternate form of the invention;

FIG. 6 is a fragmentary cross section on line 6-6 of FIG. 5;

FIG. 7 is a view similar to FIG. 5 but showing a modified construction; and

FIG. 8 is a cross section on line 8-8 of FIG. 7, but on a larger scale.

More particularly describing the invention, numeral 11 generally designates a case and within this is a phonograph device .12 which anay comprise a spring-driven combined turntable and phonograph record, 13, a needle 14 engageable with the record together with a pivotally mounted tone arm 15 which carries the needle and which is stressed to bear upwardly against the undersurface of ice a diaphragm 16. The latter is cemented to the upper edge 17 of the side wall 18 of the case and in effect encloses the working parts of the phonograph. The latter may be of the type shown and described in the copending application of Golda A. Duncan and Robert .N. Aleson, Ser. No. 603,244, filed Dec. 20, 1966. The diaphragm, which may be a thin sheet of cardboard, is thus driven by the tone arm in response to the vibrations of the needle following a sound track in the record and due to the construction of the tone arm the vibrations of the needle are necessarily amplified as they are transmitted to the diaphragm. The diaphragm is shown as generally pear-shaped in plan, which is the general shape of the case, and it may be described as having a main portion 20 of relatively large area and an auxiliary portion 21 to one side thereof which is of relatively small area.

It is a feature of the invention that I provide an opening 22 in the auxiliary portion of the diaphragm, that is, to one side of the main portion, although, if desired, several smaller openings might be provided in place of the single large opening. The opening is shown screened by .a piece of cheesecloth 23 and this is merely for the purpose of keeping foreign matter out of the interior of the case since it is customary in many instances to utilize the devices in stuffed toys and the like.

By providing an opening (or openings) in the diaphragm, the latter is permitted freer movement, since it no longer forms one wall of a completely sealed chamber as would be the case where the opening not present. Thus the movement of the diaphragm is not damped or interfered with by any air cushion behind since when air is compressed by inward movement of the diaphragm it easily escapes through the opening in the diaphragm, and conversely when air is decompressed within the case, air may move inwardly through the opening in the diaphragm.

In conjunction with the apertured diaphragm, as a means of amplifying the sound and improving the op eration of the device as a whole, I provide an enclosure and baffie means 25 and this includes an enclosure 26 which has a continuous side wall, the edge of which is cemented in place against the upper surface of the diaphragm immediately over the upper edge of the side wall of the main portion of the case and a main wall 27 which is spaced a substantial distance from but is generally parallel to the diaphragm. This main wall is interrupted by holes 28 of any suitable size and configuration over the main section 20 of the diaphragm but is not .apertured directly over the opening 22 in the diaphragm. The means 25 includes a partition or baflle 30 in the form of a partial partition wall extending between the Wall 27 of the enclosure and the diaphragm and this can be cemented at both its upper and lower edges or formed integral with wall 27 and cemented to the diaphragm. The baffie is located between the main and auxiliary sections of the diaphragm and has its ends spaced inwardly of the side wall 26 of the enclosure leaving a space 31 at each side establishing communication between chamber 32 over the main portion of the diaphragm and chamber 33 over the opening 22. The layers of compressed and decompressed air or sound waves enter the chamber 33 where they echo and re-echo against the hard, smooth interior walls of the enclosure with some escaping through the spaces 31 at each end of the baflle into the larger chamber 32 beneath the perforated portion of the enclosure. As the sound waves are of a very diverse character, that is, of various frequencies, the echoing and re-echoing insures that a large part of these will fortuitously become superimposed on sound waves generated a fraction of a second previously. Even though the superimposition is accidental and in spite of the fact that some patterns seem to decrease the amplitude, enough sound waves become superimposed at bafile points to create an actual increase in amplitude of the sound waves. The frequencies that are diminished occur so rapidly that the diminished amplitudes are to a large extent drowned out by the increased amplitudes just as a high trumpet drowns out a low flute. The effectiveness of the device is believed to be in direct proportion to the frequency, that is, the higher the frequency the more often that additive frequencies are encountered. In other words 2000 c.p.s. sound will be amplified twice as much as 1000 c.p.s. sound.

As an alternative form, in FIGS. 5 and 6 I show an extremely thin flexible plastic sheet 40 covering the opening 22A in a diaphragm 16A, and while this does not permit passage of the air through the opening, since it is now closed by such plastic, the plastic is so lightweight, thin and flexible that it compensates for the compression and decompression sound waves generated by the diaphragm by rapidly moving in response thereto. Thus, although the sheet 40 seals the opening in the diaphragm, the sound waves are, in effect, sti-ll passed therethrough. At the same time the sheet 40 serves to keep the case sealed against entrance of foreign matter.

A further modification is shown in FIG. 7 wherein I perforate the diaphragm, here designated 16B, in the region 21B with a multiplicity of very small holes 44. These holes are made small enough to keep out foreign matter from the interior of the case and should be as small as or smaller than the openings in the cheesecloth 23 previously referred to whereby the diaphragm serves as its own screen.

Another feature of the form of the invention shown in FIG. 7 is the concave-convex sound baflle 45 which is concave on the side facing the apertured part of the diaphragm. This baffle extends between the diaphragm and the wall 27 of the enclosure 26 (not shown in FIG. 7) as a partial partition and serves to reflect sound waves in a somewhat different manner than a straight bafiie.

Although I have shown and described preferred forms of my invention, I contemplate that various changes and modifications can be made therein without departing from the invention.

I claim:

.1. In a phonograph suitable for use in toys, a case having a relatively thin sound diaphragm wall, a phonograph record and record play means in said case including a member operably interposed between the record and diaphragm wall for driving said wall, said diaphragm wall having a substantial-sized opening therein, an apertured enclosure mounted on said case exteriorly of said diaphragm wall and cooperating therewith to form a chamber, said opening being located adjacent one edge of the diaphragm wall and a portion of the enclosure opposite the opening being imperforate,

and a bafifie wall between the diaphragm wall and the enclosure adjacent the inner edge of the opening in said diaphragm wall partially enclosing the space between said diaphragm wall and the portion of the enclosure opposite said opening.

2. The phonograph set forth in claim 1 in which the opening in said diaphragm wall is screened.

3. The phonograph set forth in claim 1 in which the opening in said diaphragm wall is closed by a relatively thin, highly flexible sheet.

4. In a phonograph suitable for use in toys, a case having a relatively thin, sound diaphragm wall including a main portion of relatively large area and an auxiliary portion to one side thereof of relatively small area, said auxiliary portion being apertured, a phonograph record play means in said case including a member operably interposed between the record and the main portion of the diaphragm wall for driving said wall, an enclosure mounted on the case over said diaphragm and cooperating therewith to define a chamber, said enclosure being apertured opposite the main portion of the diaphragm and imperforate opposite the auxiliary portion of the diaphragm, and a baflle between the enclosure and the diaphragm wall along the juncture of the main and auxiliary portions partially but not wholly divides said chamber into two chambers.

5. In a phonograph suitable for use in toys, a substantially closed case having a relatively thin, sound diaphragm wall, a phonograph record and record play means in said caseincluding a member operably interposed bewteen the record and a given portion of the diaphragm wall for driving said wall, said sound diaphragm Wall having a perforate area of substantial size located laterally of said given portion thereof, an enclosure mounted on said case over said diaphragm wall and cooperating therewith to define a chamber, and a partition wall bafile extending between said enclosure and said diaphragm wall and located between the perforate area of the diaphragm wall and said given portion thereof, partially but not completely dividing said chamber into two chambers, said enclosure being apertured opposite said given portion of the diaphragm imperforate opposite said perforate area of the diaphragm wall.

6. The phonograph set forth in claim 5 in which said partition wall baffle is curved.

References Cited UNITED STATES PATENTS 634,326 10/1899 Cridge.

FOREIGN PATENTS 1,43 6,696 1965 France.

LEONARD FORMAN, Primary Examiner.

R. A. FIELDS, Assistant Examiner. 

